The VIN_3V3 voltage is connected to the VOUT_3V3 output by a single FET switch (S2 in Figure 9-40).

The enabling of the switch is controlled by the core digital circuitry and the conditions are programmable. A supervisor circuit monitors the voltage at VOUT_3V3 for an undervoltage condition and sets the external indicator RESETZ. The RESETZ pin is active low (low when an undervoltage condition occurs). The RESETZ output is also asserted when the MRESET input is asserted. The MRESET input is active-high by default, but is configurable to be active low. Figure 8-1 shows the RESETZ timing with MRESET set to active high. When VOUT_3V3 is disabled, a resistance of RPDOUT_3V3 pulls down on the pin.